BIODIVERSITY
THE VARIETY OF LIFE ON EARTH AND THE ESSENTIAL
INTERDEPENDENCE OF ALL LIVING THINGS
Learning Goals & Success Criteria
Understand the variation of life on the planet
Describe the interdependence of living organisms
Describe the major threats to biodiversity
Variation of Life on the Planet
The HUGE variation of life on the planet
Common Name: Brown Antechinus
Size: 70-140mm (~28g)
Conservation Status: Least Concern
Distribution: Northern & Eastern Australia
Habitat: Woodland and forest habitats
Antechinus stuartii
The HUGE variation of life on the planet
Common Name: Red Kangaroo
Size: Males up to 1.4m and 92kg
Conservation Status: Least Concern
Distribution: Semi-arid and Arid regions of Australia
Habitat: Sparsely wooded or open plains;
grassland, shrubland, desert, woodland and open
forest, and are most common in open savanna
woodland.
Macropus rufus
There is diversity in Aquatic Ecosystems
There is diversity in Terrestrial
Ecosystems
Biodiversity Hotspot
A biodiversity hotspot is a biogeographic region that is both a
significant reservoir of biodiversity and is threatened with
destruction.
The term ”biodiversity hotspot” specifically refers to 25 biologically
rich areas around the world that have lost at least 70 percent of their
original habitat.
Terrestrial biodiversity hotspots
3 Levels of Biodiversity
Genetic Diversity
Different genes and
combinations of genes
within populations
Different genes and
combinations of genes
within populations
Species
Definition:
Organisms that have the
potential to interbreed in nature
and produce viable fertile
offspring
Population
Definition:
A group of individuals of the
same species that live in the
same area and interbreed,
producing fertile offspring
Species diversity
A number of different
species represented in a
given community
Ecosystem diversity
The variation of the
ecosystems found in
a region
Global Ecosystem Diversity
How diverse is the ocean?
The ocean is not just the
coral reef…
There is the open ocean; the
Antarctic; deep ocean;
equatorial ocean.
Each of these different
habitats provides different
diversity of species
Global Ecosystem Diversity
How diverse are the
deserts?
The desert is not just sand…
There are also ice deserts;
stony deserts; hot and dry;
arid; coastal deserts; cold
deserts.
All these different types of
deserts support very
different species
Global Ecosystem Diversity
How diverse are the ice
caps?
The organisms that inhabit
the Antarctic are very
different to those that live in
the Arctic.
It’s not just the ice – what
about under the ice?
Global Ecosystem Diversity
How diverse are our forests?
Forests are not just the rainforests…
There are temperate forests; mangrove
forests; eucalypt forests; melaleuca
forests; heathland – and that’s just
Australia.
All these different types of forests
support very different species
Which is more diverse?
Which is more diverse?
Which is more diverse?
Which has more biodiversity?
Classification of organisms
There is biodiversity across
the classification system.
Vertebrates have 5 classes:
Mammals
Amphibians
Reptiles
Birds
Fishes
How many species in each of
these classes?
BIODIVERSITY LOSS
WHAT IS CAUSING THE LOSS OF BIODIVERSITY ON OUR PLANET?
Biodiversity Loss
The main cause of the loss of
biodiversity can be attributed to
anthropogenic influences (the
influence of human beings) on the
world’s ecosystems.
Human beings have deeply altered the
environment, and have modified the
terrestrial and aquatic ecosystems in
many ways.
Threats to Biodiversity
The HIPPO acronym is a
good way to remember the
five main threats to
biodiversity
Habitat Loss
Invasive Species
Pollution
Population (overpopulation)
Overfishing, overuse,
overexploitation
1. Habitat Loss
Habitat loss is the greatest reason
for biodiversity loss
Long term Habitat Loss in NZ
2. Invasive/Exotic Species
Introduced usually by human
activities
They are generally thought to cause
economic or environmental harm
Are all invasive/introduced species
harmful?
Some introduced species are beneficial to society
Introduced species provide food, shelter, medicine, and aesthetic
pleasure
Some organisms are introduced to control the populations of invasive
species - biocontrol
Cactoblastis cactorum: Cactus Moth
Prickly Pear cactus introduced to Australia
It very quickly took over – particularly in NSW
Cactoblastis cactorum was then introduced to Australia to control the Prickly Pear. It has
managed to kill off over 99% of prickly pear in NSW.
• Mango
• Beef
• Bacon (what’s not
to love about
bacon…)
• Avocado
• All introduced to
Australia and
enjoyed on dinner
plates around the
country
3. Pollution
Pollution: oil spills, human agricultural
waste, fertilisers, pesticides, acid
deposition, greenhouse gases, etc
Caused by human activities
Has a negative effect on biodiversity
4. Population (overpopulation)
3.7 billion and counting
The expansion of human population
and affluence, especially in the
developing world harms natural
ecosystems
Compare to our Biodiversity Hotspots
Can you see the
problem?
5. Overharvesting, overuse,
overexploitation
Overhunting, overfishing, destructive
harvesting practices (cyanide,
dynamite), illegal trade, exotic pet
industry
Compare fish landings in tons from
1910 and the late 1960s/early 1970s.
What do you think caused the
significant drop in fish landings
between 1965 and 1975?
What do you think is the outcome for
fish this century?